ftv _ = []
subst s (TupleType (t1, t2))= TupleType (subst s t1, subst s t2)
subst s (ListType t1) = ListType (subst s t1)
- subst s (FuncType t) = FuncType (subst s t)
+ subst s (FuncType t) = FuncType (subst s t)
subst s (t1 ->> t2) = (subst s t1) ->> (subst s t2)
subst s t1=:(IdType tvar) = 'Map'.findWithDefault t1 tvar s
subst s t = t
infer e2 >>= \(s2, t2, e2_) ->
pure (compose s2 s1, TupleType (t1,t2), TupleExpr p (e1_,e2_))
+ LambdaExpr _ _ _ = liftT $ Left $ Error "PANIC: lambdas should be tasnformed"
+
FunExpr p f args fs =
lookup f >>= \expected ->
let accST = (\(s,ts,es) e->infer e >>= \(s_,et,e_)-> pure (compose s_ s,ts++[et],es++[e_])) in
let given = foldr (->>) result argTs_ in
(case expected of
Nothing = pure zero
- Just expected_ = lift (unify expected_ given))
- >>= \s3 ->
+ Just (FuncType expected_) = lift (unify expected_ given)
+ Just expected_ = lift (unify expected_ given)
+ ) >>= \s3 ->
let ftype = subst (compose s3 $ compose s2 s1) given in
- generalize ftype >>= \t->
+ (case ftype of
+ _ ->> _ = pure ftype
+ _ = pure $ FuncType ftype
+ ) >>= \ftype_->
+ generalize ftype_ >>= \t->
putGamma outerScope >>|
changeGamma (extend f t) >>|
- pure (compose s3 $ compose s2 s1, FunDecl p f args (Just ftype) tVds stmts_)
+ pure (compose s3 $ compose s2 s1, FunDecl p f args (Just ftype_) tVds stmts_)
instance type [a] | type a where
type [] = pure (zero, [])